Every tuner's nightmare, especially when dealing with high-compression engines. Catastrophic engine failure basically means "all hell breaking loose" within an engine. It can have singular or multiple causes, but usually concludes with the utter destruction of the entire engine and all of its component parts. Occasionally something may be salvageable, but as a whole, the engine is rendered useless. Due to the explosive, high-pressure nature of internal combustion engines, a stray fragment of metal can have devastating consequences. Occasionally, a stray bird can wreck a jet engine. Common causes of engine failure in cars include:

  • Failing to change the oil, or a failure of an oil pump. A decent amount of clean oil is necessary for an engine to function smoothly. If the oil pump seizes, or a neglectful owner decides to blow off an oil change long enough, the engine can seize, reaching temperatures high enough to literally fuse pistons and cylinders into one. Remember those Castrol Syntec commercials? Usually this is rare, and there will probably be warning signs before it happens. Even so, it's a bad idea to be lazy with oil changes, as dirty oil erodes the components of the engine, lowering its compression ratio and fuel efficiency.
  • Radiator failure, or persistent overheating in general. If the radiator is not functioning properly to cool the engine, the oil within the engine can reach temperatures high enough to lose viscosity. The results will be similar to above.
  • Detonation. Detonation occurs when the fuel/air mixture in the cylinder ignites before it is supposed to. In essense, the mixture explodes before the spark plug provides the spark, which smacks the piston around like a $2 whore (sorry, I had to say it). The result is often a "pinging" noise (depending on the severity of the explosion and where the piston is when it occurs), which is the sound of your piston, bearings, and connecting rods resonating from the intense shockwaves of an uncontrolled explosion. If detonation is sufficient to actually dislodge an engine component, you can at least kiss the cylinder (and probably the whole engine) good bye.